Automatic control for internal-combustion engines



Feb. 1s, 1,930.

D. DAvlsoN ET AL 1,747,578

AUTOMATIC CONTROL FOR INTERNAL COMBUSTION ENGINES Filed Jan. .15, 1927 ssheets-Sheet 1 ATTORNEYS.

Feb. 18, 1930. D. DAvllsON ETAL 1,747,578

AUTOMATIC CONTROL FOR INTERNAL COMBUSTION ENGINES Filed Jan. 15, 1927 3Sheets-Sheet 2 A TTORNE YS.

Feb. 18, 1930. D. DAvlsoN Er AL 1,747,578

AUTOMATIC CONTROLFOR INTERNAL COMBSTION ENGINES Y Filed Jan. 13. 192'? sVsnee'sshe' 3 TORNEYS.

Patented Feb.. i3, E93@ DAVID DAVISON, OF OAKLAND, AND WILLIAM L.COR-SON, DECEASED, LATE 0F ALA- MEDA, CALIFORNIA, BY JOSHUA A. ROBERTS,ADMINISTRATOR, OF ALAMEDA,V CALIFORNIA, ASSIGNORS TO UNION GAS ENGINECOMPANY, OF OAKLAND, CALI- FORMA, A CORPORATION 0F CALIFORNIA AUTOMATICCONTROL FOR INTERNAL-COMBUSTION ENGINES Application led January13,-1927. Serial No. 161,006.

This invention relates to Diesel engines of the solid or mechanicalinjection type and particularly to automatic fuel regulation andcontrol.

Diesel motors of the mechanical injection type are provided with a spraynozzle, a valve in the nozzle to regulate the discharge of fuel, a pumpto deliver fuel.to the nozzle and means for regulating the quantity offuel delivered to the nozzle. Engines of this type are usually subjectedto considerable variations in speed and load conditions when inoperation and means must, accordingly, be provided to vary the quantityof fuel injected.

Varying load and speed conditions are ordinarily taken care of either byregulating the lifting period of the spray nozzle valve or by changingthev quantity of fuel delivered to the spray nozzle by the fuel pump. Inactual practice, it has been discovered that a change in the quantity offuel injected or regulation of the spray valve liftor, in other words,increasing or decreasing the spraying or injecting period is notsufficient if efficiency and good combustion is considered as anotherfactor enters to-wit: that of pressure regulation. It has been foundthat the pressure on the fuel should reach maximum during a prolongedspraying period and considerably reduced during a shorter sprayingperiod. rlhis is due to the fact that a greater quantity of fuelrequires more energy or pressure to insure atomization, while a smallerquantity of fuel requires less energy or pressure. lt has also beendiscovered that better control and efficiency is attained when thespraying period and the quantity of fuel injectedare controlled inunison. Again, it has been found that the pressure on the fuel should bechanged as the spraying period and the quantity of fuel is varied andfurther that the spraying period, the quantity of fuel injected and thepressure maintained should be changed with variations in speed and load.

The object of the present inventionis to generally improve and simplifythe construction and operation of -regulating devices of the characterdescribed; to provide means whereby the spraying period, the quantity offuel injected and the pressure maintained may be regulated in unison andfurther t0 the spray nozzle and aportion of the mech-l' anism actuatingthe same,

Figure 4 is an enlarged sectional view of the fuel punip and a portionof the mechanism actuating the same, v

Figure 5 is an enlarged sectional View of the governor.

Referring to the drawings, in detail, and particularly Figure 1, Aindicates the cylinder of a Diesel engine; B the head; C the spraynozzle; D the fuel pump; E the cam shaft whereby the exhaust and inletvalves of the motor are actuated and F a governor which is driven by thecam shaft 'and the function of which will hereinafter be described. f

The spray nozzle is best illustrated in Figure 3 of the drawings. Itconsists of a body portion 2 which projects through the head B of thecylinder and which terminates in a spray tip 3. Mounted interior of thebody and normally forming a closure for the spray tip is a needle valve4. This valve projects through a stuffing box 5 and its upper orprojectingend is provided with a collar 6 which is engaged by awedge-shaped member 7. Engaging the wedge-shaped member is anintermediate rocker arm 8 which, in turn, is actuacted by a main rockerarm 9'. This rocker arm is, in turn, actuated by a fuel cam 10I securedon the cam shaft E and the needle valve is thus intermittently raisedwith relation to the spray tip so as to permit injection of the fuel.The quantity of fuel injected de- @ne form as engines o thischaracterlaresubjected to varyingload conditions means mustbe employed forregulating ,the opening period of terminesthe power output ofthecylinder and the valve. The means employed in the. present instance, isthe wedge-shaped member 7.

' .This member is actuated bythe governor F through a rocker arm and aseries of link connections, as Will hereinafter be .described.`

Sufiiceth to say that a longitudinal movement is imparted to the Wedgemember 7 and that this determines the lifting or opening period of thevalve.

Inactual practice, ithas been found that vvit `is not only necessary to.regulate the quantity of fuel injected, but itis also necessary toregulate the quantity of fuel delivered to the spray nozzle and furtherto regulatethe pres sure maintained'on the fuel. Themeans` employed inthe 'present instance is a variable dischargeor metering pump,previously referred to and indicated atD. This pump is bestillustratedin Figure 4and it consists of a cylinder or body portion 11in which is formed a cylindrical chamber 12." The upper" endof thiscylindrical chamber is provided with a stuffing box 13 through whichextends a plunger 14. This plunger .is pivotally ,con-

nected as at 15 (see Figure '1) with'a strap 16 which, in turn, isconnected with an eccentric 17 secured on the cam shaft. This eccentricimparts a reciprocal movement to the plunger and fuel in the form ofoil' or the likelis thus intermittently admitted and discharged by thepump. The fuel is admitted through an inletvpipe 18 and dischargedthrough a pipe 19 which connects with the upper end of the spray nozzleC, as indicated at 19. One side of the cylinder 11 is extended as shownat 20 and this extension forms a housing for an inlet valve 21 and adischarge valve 22, these valves being interposed between the respectiveinlet and discharge pipes 18 and 19, as illustrated.

An intermediate chamber 23 is formed between the valves and thiscommunicates with the cylindrical chamber 12 throughA means :of a port24. The fuel is admitted through the inlet pipe 18 during upwardmovement stroke vofthe, plunger 14 permits a certainl ofthe pump plunger14 as the inletl valve will be opened both by suction and mechanicaloperation, during reversemovement the oil admitted will be dischargedpartly through the inlet valve and-partly through the dis'- charge valve22 during the return stroke ofv the plunger. In fact the lvarieddischarge or metering action obtainedby the pump Adepends uponthe.mechanical closing of the inlet valve, as retension of the inletvalve inopen position during a portion of the return quantity of the oiladmittedto be returned.

" through .the inlet valve to the suction line 18 and the remaining oilto be. discharged through the valve 22 when the inlet valves shaft 30and the eccentric 29 in'the direction' closed.' v The .mechanicalvoperation of the inlet valve'A is .obtained by the, employment of aplunger rod 25. -This extends through a' vstuiring box 26 mounted in thelower end of the housing 20 and it is connected through .means f 4'alink 27 to a rocker arm 28 which oscillates' on an eccentric 29 which issecured on a controller shaft 30 hereinafter to be described. Theopposite end of the rocker arml 28 is connected through means of a link31 (see Figure 1) with the plunger V14 at the v point indicated at 32. Areciprocal movement is thus imparted tothe link in unison with themovenient of the plunger 14 and this reciprocal movement is, in turn,transmitted to oscillate the vrocker arm 28. This, in turn,

er 25 which alignsjv'vith the inlet valve 21 and by regulating theposition of the rocker arm. 28 the closing period ofthe inlet valve 21.

may be determined and similarly theyquantifty of oilbypassedor returned;1 If it is de- .imparts a reciprocal movement to the plungsired toretardclosing of the inlet# valve during `thedownward 4ordischarge stroke ofthe plunger 14, it is merely necessary to rotate the to the controllershaft 30 and its outer end swings overa segmental rack bar 34 with whichit may be interlocked by means of a spring pawl 35. Hence, by swingingthe lever 33 manually, any position of the shaft 30, eccentric 29 andplunger 25 may be obtained.

The other means employed forV controlling,

the closing of thev inlet valve is-the governor F. This governor impartsa rockingvmo'vement 37 controller shaft 30. This crank arm is connectedwith the arm 36 through means ofv a to an arm 36 which is secured on ashaft crank arm 38 is secured on the end of the 1F15 v link39 androcking movement of the .arm

36 is thus transmitted to elevate or lower the eccentric, the rocker arm28 andthe plunger' 25v and means have, accordingly,

een provided* Wherebythe closing 'period' of the valve may be eithermanually or automatically regulated. The arm 36 which is actuated by thegovernoralso'serves a func-v tion of controlling the position of thewedge member 7 whereby the openingv period of the'fuel` injecting valveor spray nozzle is controlled. This is accomplished by providing abellcrank or the like such as' indicated at 40. This s pivotally mountedas. atfli on top of the cylinder head. The upper end of the bellcrank isconnected with the wedge member 7 through means of ailink 42 and thelower end of the bellcrank is connected with the arm 36 through means ofa link 43. Hence, when rocking movement is transmitted to the arm 36through means of the governor, two automatic regulations aresimultaneously attained, to-wit: automatic regulation of the quantity ofthe fuel discharged by the pump andautomatic regulation of the fuelinjector or spray nozzle valve.

The governor employed is also an important feature of the presentinvention as it does not only serve the function `of automaticallyregulating the injection or spray nozzle and the quantity of fueldelivered thereto, but it also serves the function of maintaining suchautomatic regulation during a wide range of engine speeds. AAdescription of the governor mechanism is, accordingly, thoughtnecessary and reference will be made to Figure 5.

By referring to this drawing, it will be noted that the governorconsists of 'a lower housing section 45 and an upper housing section 46.Extending through these housing sections is a, governor shaft 47 andsecured thereon in the usual manner is a cross head arm 48 in the outerends of which is pivotally mounted as at 49 bellcrank arms 50 whichcarry ily halls 51.. These are Connected in the usual manner by tensionsprings 52 'and they, furthermore, function in the usual manner, thatis, they are actuated by centrifugal force during the revolving movementof the shaft 47 and as such have a tendency to swing outwardly againstthe tension of the spring 52. -The inner ends of the bellcranks areprovided with rollers 53 and these in turn,`

shaped rocker arm 56 secured "on the inner end of the shaft 37 andengaging an" annular groove or collar 57 formed on the-sleeve 55.

The-outward movement of the iy balls 56 andthe downward movement of thesleeve 55 is in the present instance, resisted by a plu-' rality ofsprings such as indicated at 58 and 59. The lower ends of the springsare supported on the plate 60 which is lvertically slidable on thegovernor shaft 47, while the upper ends engage a plate 61 which, inturn,

60 and 61 together with the springs 58 andl 59 are secured againstrotation by passing rods 63 through the springs 58 and the plates and bysecuring one of the rods to the governor housing. This feature is,however, of no material importance and further description thereof isthought unnecessary.

An important feature is, however, that of providing means whereby thetension of the springs 58 and 59 may be varied. The means employed inthe present instance is a crankv arm 64 which engages the lower plate60. This crank arm is secured on thelshaft 65 which is journalled inthegovernor housing 45 and extends through one side thereof. The outer endof this shaft is provided with a manually controlled lever 66 (seeFigure l) and this lever, in turn, carries a pawl 67 which engages arack bar 68. The position of the controlling lever 66 and the rocker arm64 maythus be determined and maintained and the tension of the springs58 and 59 is, accordingly, regulated. These springs coact with thegovernor spring 52 through means of the sleeve 55 and the governorbellcranks 50 and more or less resistance may Athus be imposed againstthe centrifugal action Aoutward orv centrifugal movement of the Hy balls56 is thus placed at a minimum and the speed of the engine will be slow'as-the y balls will swing outwardly the moment a predetermined speed isexceeded. Such outward movement is transmitted to the sleeve 55 andthrough the rocker larm- 56 and shaft.

37 to the controlling arm 36. This, in turn, actuates the fuel pump andthe spray nozzle in such a manner that the spray valve is given itsshortest opening period and the pump its smallest discharge. y

On the other hand, if maximum or full speed is required, the controllinglever is swung to lits uppermost position shown in Figure 1. Suchmovement placesthe springs 58 and 59 under maximum compression and agreater load is thus placed on theflyballs of the governor and they willbe restricted to outward movement vuntil a maximum speed is obtained. lAny intermediate speed may similarly be maintained by moving thecontrolling lever to any intermediate position between the maximum andminimum speeds.

It is'thus seen that the pump suction valve and spray nozzle fuel valvecontrols are synchronized and operated by the governor ysimultaneouslyat minimum and maximum governing. This is of further importance as 'iteliminates thebypassing of high pressure fuel.l There is, however,installed, an emergency relief valve in the oil delivery pipe 19, butthis functions very rarely and as it is more or less a common expedientin installations of this character, illustration thereof, has beeneliminated. v

Itwas previously stated that the'quantity of fuel discharge by the pumpwasunder'b'oth ma-nual and automatic control. Such an arrangement "isalso provided in conjunction with the fuel or spray nozzle valve,'thatis, the opening period of the valve is'both automatic and' manuallyregulated. The automatic control, throughmeans of the governor-hasalready been described. The manual control is only emplo ed whenstarting, as greater quant1ties ofv uel is required.v It consists of amanually lcontrolled lever 70 pivotally mounted on top .of the cylinderhead as indicated at 71. This lever is connected with a r`bellcrankthrough. means of a link 72. The end of the link which connects with thebellcrank 'is slotted as shown at 73 and asmatic action of the governor.

such does not interfere with the normal autoture is required inconnection with the manually control to-wlt: an extensible coupling onthelink or rod 43 as indicated at 74 (see Figures lland- 2) The link orrod 42 is divided into two sections, theA uppermost section beingscrewed ory otherwiseconnected-.with a nut which extends into and issecured in the upper end of the coupling 74. f .The lower end of the rodprojects through the coupling 74 and is slidabletherein. l

A head member is secured onthe lower section of the/rod and a 'spring'77 is interposed .between said head member and the lower end n40iof'thecou ling. lHence,whenstartingthe enginev an requiring aA greaterquantity of fuel, it is only. necessary to pull the l'controlling lever70 downwardly inthe direction of arrow B (see Figure 1).' Such adownward movement i-s transmitted through the link 7 2`to pull therocker arm 40 in a `forward direction thereby placing the wedge 7 in.

a position where the opening periody of the needle valve will beincreased and the quantity of fuel, injected proportlonately 1ncreased.The moment'the engine is startedthe controlling lever 70 is swung backto n ormal position and automatic regulation is then ldepended upon. Thespring couplmg 74 permits such temporary forwardmovement of'4 the crankarm 40 due to the fact that` the coupling can move upwardlyfwithrelation to the lower section of the rod 43. When the bellcrank isreturned to normal position by returning the controlling lever to normalpositiointhe head member 7 6 engages the nut 5 andthe rodwill'thenfunction as a rigidv unit. It was previously stated thatpressure regulatonof the fuel was one of the important Another fea-l-understood that maximum quantities of fuelL is injected during maximumengine speed'and loads and that the vquantity ofpfuel injected duringreduced loads and speeds is materially decreased. Actual experience hasdetermined that the best results are obtained as far as efliciency andgood combustion `is concerned when the pressure on the fuel is increasedduring maximum injection of fuel and proportionately decreased duringreduced inject1onof fuel. This is due to the fact that more venergy inthe form of pressure is required to atomize a greater quantity of fueland it is alsodue to the fact thatvjperfect atomization of asmallquantity vof fuel ish causes slower combustion during idling speedswhich is a 'desirable feature, while more or less perfect atomizationcauses rapid combustion with a tendency towards pinging or knocking.Itis for this reason that .pressure regulation is maintained.

It is usually stated and commonly thought that liquids areincompressible. VIt is,'how

ever, known thatA water is compressible to a tained by' variabledischarge of the metering pump. When the discharge of the pump ismaintained at maximum, the greatest ressure is obtained on the eil asagreater ody of oil is forced intothepressure lines or `pipes andthespray nozzles which have-a given or predetermined capacity. On the otherhand when the discharge ofthe pump is maintained at a minimum, a smallerquantity of vnot desired when running under-slower speeds 1 or idlingcondltlons, ascoa'rser atomizatlon l oil is discharged in the pressureline and spray nozzle and the 'pressure will, accordingly, drop to aminimum as a smaller quantity of oil is 'delivered into a space ofpredetermined capacity. It is, accordingly, evident that variation inpressure is obtained due to the Variable disrirge of the pump and thecompressibilityf' the oil and it is further videntthat. the pressurewill be at minimum when the discharge ofthe pump is the smallest andthat a maximum pressure will be obtained when the discharge of the pumpis the greatest.

From the foregoing description, it will be understood that a controllingmechanism has been provided which is both manual and governor, it ispossible to simultaneously vary the spraying period, the quantity of o1linjected and the pressure maintained and further that such'control maybe automati- 5 cally maintained during all speed ranges between themaximum and minimum speed ofv the engine. While certain features of thepresent invention are more or less specifically described, I wish itunderstood that various changes may be resorted to within the scope ofthe ap- A pended claims. Similarly that the materials and finishes ofthe several parts employed may be such as the manufacturer may decide lor varying conditions or uses may demand.

Having thus described the invention, what I claim and desire to secureby Letters Patent is l. In a mechanical injection Diesel engine, 2o aspray nozzle, a pump adapted to deliver' fuel thereto, a valve in thespray nozzle, automatic actuated means to vary the opening period of thevalve and the quantity of fuel delivered by the pump in unison, a manualcontrol connected with the valve to vary the opening periods, a manualcontrol on the pump to vary the quantity of fuel delivered, said manualcontrols being operable independent. of the automatic control and beingalso operable independently of each other.

- 2. In a mechanical injection Diesel engine, l a variable dischargefuel pump, a spray nozzle having a valve, means to vary `the openingperiod ofthe valve, a governor driven by the engine, a manual controlfor the governor whereby the governor m-ay be adjusted to act at anyspeed range between a maximum and minimum speed, and4 means actuated bythe governor at maximum, minimum, or any intermediate speed whereby thequantity of fuel discharged by the pump is increased as the valveopening periodincreases sol that synchronous co-operation of the pumpand valve is insured. DAVID DAVISON. l

. JUSHUA A. ROBERTS, Administrator of William Oolson, Dea

cewsed;

